This invention relates to air conditioning systems for multi-storey buildings.
In buildings of this kind, working and/or living spaces (hereinafter called "occupied spaces") are usually located in peripheral areas of the building around a central core area which houses elevators and other service facilities. The core area normally represents a fairly constant cooling load in the building; that is, it requires year round cooling. The occupied spaces on the other hand have varying heating and cooling requirements depending on such factors as ambient temperature, heat gain from solar radiation, lighting and other sources within the building, and the preferences of individual occupants of the spaces. In multi-storey buildings in North America, the sources of heat gain are normally such that cooling is the predominant requirement in the peripheral occupied spaces.
In view of these considerations, conventional air conditioning systems have been designed primarily for cooling and have included means for so-called "terminal reheating" of air in the occupied spaces of the building as required. Early systems relied on a single fan arrangement for delivering substantial volumes of cooled air both to the core and to the peripheral spaces of the building. In more modern systems, each floor of the building has an individual fan room provided with a chiller from which cooled air is delivered to the individual occupied spaces on that floor and the spaces have individual air re-heating devices. A separate fan system delivers cooled fresh air to the core of the building.
All of these systems operate on the principle of cooling the whole building and locally re-heating specific areas according to requirements. Accordingly, these systems are wasteful of energy and expensive to operate. Energy is required to cool the air delivered to the occupied spaces and core area of the building, and further energy must be expended to re-heat that previously cooled air in the occupied spaces when required.